The SENIOR POISE trial showed that perioperative metoprolol in non-cardiac surgery patients at cardiovascular risk increased the rate of stroke. The presumed mechanism of this adverse outcome was:
- A Metoprolol-induced atrial fibrillation leading to cardioembolic stroke
- B Metoprolol's direct vasospastic effect on cerebral arteries
- C Beta-blocker-induced hypotension and bradycardia causing cerebral hypoperfusion, particularly in the setting of intraoperative hypotension ✓
- D Rebound tachycardia postoperatively after metoprolol withdrawal
Explanation
The POISE trial (2008, 8351 patients) showed that high-dose extended-release metoprolol started within 24 hours of non-cardiac surgery reduced the primary composite (non-fatal MI) by 27% but significantly increased stroke (2.0% vs 1.0%) and total mortality. The mechanism of increased stroke was beta-blocker-induced hypotension and bradycardia, reducing cerebral perfusion pressure below the autoregulatory threshold in patients with pre-existing cerebrovascular disease. Current guidelines recommend against initiating beta-blockers within 24 hours of surgery; if beta-blockers are to be used, they should be started at least 1–2 weeks preoperatively at low doses.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
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Written and medically reviewed by the StethoPrep medical team.